return Sets.newHashSetWithExpectedSize(expectedSize);
  }

  /** Returns the platform preferred implementation of a thread-safe hash set. */
  static <E> Set<E> newConcurrentHashSet() {
    return ConcurrentHashMap.newKeySet();
  }

  /**
   * Returns the platform preferred implementation of an insertion ordered set based on a hash
   * table.
   */

  private var serverSocket: ServerSocket? = null
  private val connectionCount = AtomicInteger()
  private val openSockets: MutableSet<Socket> = ConcurrentHashMap.newKeySet()

  fun play() {
    serverSocket = ServerSocket(0)
    executor.execute {
      val threadName = "SocksProxy ${serverSocket!!.localPort}"
      Thread.currentThread().name = threadName
      try {